Method of testing electric transformers.



M. C. RYPINSKI.

METHOD 0B TESTING ELEGTRIG TRANSFORMERS. APP JGATION FILED DBO. 6, 1007.

984,1 60. Patented Feb. 14, 1911.

h WENTOR iramgzs .IBY

z/ww/ AT'TORNEY UNITED STATES PATENT OFFICE.

MAURICE C. RY' INSKI, OF PITT$BURGa PENNSYLVANIA, ASSIGNOR, BY MESNE ASSIGN MENTS, TO WESTINGHOUSE ELECTRIC 8:; MANUFACTURING COMPANY, OF EAS'I IPITTSBURGr, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

METI OD OF TESTING ELECTRIC TRANSFORMERS.

eser. 1.60.

Specification of Letters Patent.

Patented Feb. 14, 1911 Application filed December 6, 1907. Serial no. 405 440.

To uLl- 'UJh-OWL- it may ('0 near-n.

Be it known that I, ll'tiitiuon C. Rrrinsn'i, a citizen of the United States, and a resident of Pittslnirg, in the county of Allegheny and State of Pennsylvania, have in- 'ented a new and useful improvement in .dethods ot/le'etine- Eleetrie 'lransformers, of which the. tollowing a specification.

lliy iln'tlil'inli relates to methods of testing: ehK-lriea'l apparatus. and it. has for its ohjert lo prmiihan improvi d method of testing the polarity and ratio ot'ti'aiislin'ii'uition 0!? trans'lormers.

Figure l of the fitt'iillltilllILYiIlQ' drawings is a diagrauunalic i'ien sho'u'i lie the circuit eoiu eetions ot' a ystem for practicing my intention, and Fig.5 2 a similar" "lQ1Y in \vhichthe, resistances :irr so illustrated as to set Forth more i.;l ,ea|'l their relation to the rest oft-he s stem. I

Referring to the drawings,electrical en- :rgy is supplied to a substantially constant po ential line l --33 from any suitable alter; hating current soul-50., such as a single-phase generator 23. X standard testing transformer -.l having primary windings 5 and G and seeondary windings T and S, is supplied with energy from the line 1---2, across which it is vrmnerted iii multiple circuit with a transformer J, which is to he tested in order to determine its polarity and the relation of ils primary to its secondary windings.

" lhe secondary winding 10 of the trans,- form'er 9 and the secondary windings T and ot the standard transformer are connected 1v shown in 1* 1g. 2,

to each other; as clear thrmre h two equal r tances 11 and 11,

the secomlaiy windings T and 8 being illustraled as a single \vinding'in this diagram, although "the may be eouneeted either 1n series or La lnu'hiiple eireuit, as l'iereinatter' pointed out.

"The middle points of the resistanees 11 and llFare joined through a Winding 12 of a measuring instrument 13, a second winding lat of which is ccmstantly energized from any suitable source, such as a transformer 15. The instrument 13.v is so designed,'and

is provided: with the windings 12' and 141' such that its moviiug element tends to move in one (Infection orthe other according to the phase'relations of the electromot-ive on s impressed upon the windings. C0nsequently, a phase reversal is clearly indicated by a rmerse deflection. Another secondary vircuit is completed from one terminal 16 of the testing transformer through indicating v lamps 17 and 18, winding 10 of the trans- -tormer t), eomluctor 19, terminals 20 and varm 21. ot a (hmble-throw switch 21 and conductor 22 to. the other terminal 23 of the testing transformer.

in testing the transformer 9 it is first desirahle to determine the polarity of its Windinn whieh may be aeeomplishedhyso throwing' the switch arm 21 as to hridfie eontact members "20. ll hen this is done, circuit c0nnet-{ions are estal'ilished from terminal 16 of the testing tamsformer through indicating lamps 17 and 18 to terminal 24: of the transt'ormer 9, and from terminal 28 of the testingtransformer through conductor 22, contacts 20 of switch 21 and conductor 19 to the terminal 25 of the transformer 9. It isevident that either a voltage equivalent to .the sum of those produced by the two secondary ril di igs or a voltageeqnivalent to the difierenee between said voltages will be impressed. upon the terminals of the lamps 17 and 1S. If the terminal 2-1 of the transformer 9 is ot the same polarity as the terminal 16 of the. starnlard transformer, the transformer secondaries will oppose each other, and the lamps 17 will either burn dimly or groout. On the other hand, it terminal 25 is of the same polarity as the terminal 16 the secondary windings will assist'eaol'rother and a relatively high voltage 2 will be impressed upon the lamps so that they will burn brilliantly. i Having thus 'obtainedthe polarity of the transformen it remains-to determine the ratios existing betweenits primary and secondary windings. essential that the't transformer secondary windings oppose each other on account of the relation between-the resistances '11 and;

,Before this is done it is 1? and theremainderrof'the system. When ,i

movable member of the instrument will be deflected in the one-direction or the other,

according as the standardtransformer sec ondary voltage is higher or lower than the secondary voltage of the transformer 9. The constant potential of the line 1-2 being known, it is now only necessary to adjust the ratio of the standard transformer until there is no deflection of the movable member of the instrument 18. In order that this adjustment may be accurately and determiand 59.

through an angleof substantially 90 the nately accomplished, the secondary windings 7 and 8 of the standard transformer are provided with a plurality of intermediate taps 27 to 46,.inclusive, which, together with the terminals 47, 48, 49, and 50 are, severally, connected to two groups of contact members which are arranged substantially in arcs of circles and are,1'espectively engaged by movable contact arms 51 and 52. The transformer terminals which are designated by reference characters 16 and 23 are respectively connected to these contact arms.

The primarywindingsfi and 6 of the standard trmisformer are adapted to be thrown in series or multiple circuit relation by means of a switching device 53 which comprises stationary contact members 54, 55, 56. and 57 and movable contact members 58 By rotating the movable member circuit changes are effected in a well known manner. In this way, the standard transformer is adapted for use with a large number oftransformers having widely varying ratios of transformation.

It is conceivable that variations in the circuit connections of my system may be effected without departing from thespirit of my invention, and I desire that only such I limitations shall be imposed as are indicated in the appended claims.

claim as my invention:

1. The method of testing transformers which consists in s pplying energy to paralimary windings of two j g he of'which is standard, connecting thecorresponding terminals of the secondary windings of the transformers together through resistances, connecting between intermediate points in the resistances an indicating instrument that is sensitive to phase reversals, and adjusting the voltage impressed on the resistances by the standard transformer,

2 The method of testing transformers which 0I11Stl11 supplying energy to the primary windmgs oftwo transformers con- 'neotedin multiple circuit, one of said transformers 'having an adjustable secondary winding and a known polarity and ratio of ratio until said balanced condition is indicated.

3. The method of testing a transformer which consists in supplying current to its primary windings and to the primary winding of a standard transformer connected in parallel therewith, supplying current to a voltage-indicating devicefrom the secondary windings of sald transformers when connected thereto in series, opening said series cn'cult, connecting corresponding terminals of the secondary windings together through equal resistances and connecting the intermediate points in the resistance through a phase reversal indicator.

4. The method of testing a transformer which consists m supplying current to its,

pr mary winding and to the primary wind-- ing of a standard transformer connected'in multiple circuit relation thereto, adjusting the polarity of the two transformers and supplying current from both transformers,

through resistances, to an indicator that issensitive to phase reversals, and adjusting the secondary voltage of the standard transformer to balance the voltage of the ti'ansformer under test.

5. The method of testing transformers which consists in .the following steps: supplying alternating current energy to corresponding windings of two transformers in multiple circuit; connecting corresponding terminals of the remaining. windings together through equal resistances; introducing between the middlepoints of the resistancesan'electric indicating instrument that is sensitive to phase reversals, and adjusting the active turns of the winding of one of the transformers until the in a balanced condition.

strument indicates In testimony whereof, I have hereunto subscribed my name this 19th day of N ovember, 1907 MAURICE G. RYPINSKI. Witnesses H. W. Brown, BIRNEY HINES. 

